Closure for shipping containers



April 9, 1968 H. RCHER 3,377,014

CLOSURE FOR SHIPPING CONTAINERS Filed OCT.. lO, 1966 HEINZ Rm-'ER 6g: W, #JM-Mal, Val# @Amm Ar-rVS.

United States Patent V 9 12 Claims. (Cl. 22a- 5.5)

This invention relates generally to cylindrical shipping containers such as drums, and more particularly to a closure for such drums. In its more detailed aspects, it relates to a closure for shipping drums of the type used for packaging, storage .and transport of powderous, liquid and semi-liquid goods.

Shipping containers of the type to which the present invention is directed generally comprise a cylindrical body having a reinforced circumferential Ibead at each end defining .a chime. The walls of the container may be of any suitable material, but the present invention finds particular .applicability to containers in which the body is made -o-f fibre, paperboard or similar material. It is, however, equally :applicable to containers having side walls of steel or other metal.

Containers of this type are often utilized for the transport of liquid or semi-liquid goods. With such contents, difficulties are often encountered in achieving a liquidtight `seal having sufficient resistance to shocks and other heavy loads Ias may be caused, for instance, by dropping or other mishandling of .the filled container. This is primarily due to the fact that such shocks often cause deformations of the container and closure, resulting in distortion of abutting sealing surfaces through which' the containers contents may escape.

`Cover members made of sheet metal, cardboard, wood, plywood or the like have been previously used in connection with containers of this type. Such covers have been used to effect closure of the container by being introduced into the open end land -being held therein by a split contractable closing ring which engages the circumferential bead of the chime to clamp the cover into place. However, shocks .and loa-ds can bend or distort such clo-sures .in a manner which results in separation of the abutting members to result in gaps or voids which cannot `be bridged by the frigid cover member or contractable closing ring.

In view of .the foregoing, it is a primary object of the present invention to provi-de an improved closure for shipping containers which is effective to maintain the integrity of the closure seal when the container is subjected to shocks and loads which cause relative deformation of the end portions of the container. It is further contemplated that the improved construction will serve to enhance the stiffness and rigidity of the end of the container to make it more resistant to damage or deformation from handling abuse.

A further object is the provision of such a container and closure which is readily and easily stacked in interlocking relationship with other containers of the same type, thereby enhancing the rigidity of stacks of such containers and allowing them t-o be handle-d or stacked with increased safety.

Other Iobjects and advantages of the invention will become apparent upon reading the following detailed description and uponreference lt-o the drawings, in which:

FIGURE 1 is la fragmentary section of a shipping container having the closure of the present invention;

FIG. 2 is a fragmentary section similar to FIG. l illustrating a modification of the invention employing a stitfening member within the mouth of the container,

.L dce and additionally illustrating a stacking member engaging a similar container (in phantom) stacked above the first;

FlG. 3 is a fragmentary section illustra-ting .a further modification of the present invention in which a stitfening member is employed which overlies the mouth of the container;

FIG. 4 is a fragmentary section illustrating still another modification of the presentiuvention in which dual stifening members are incorporated; and

FIG. 5 is a fragmentary perspective illustrating a po-rtion of the closure membrane utilized in the present -invention, with its various layers peeled back for clarity.

While the invention will be described in connection with preferred and alternative embodiments, it will be understood Ithat the invention is not to be so limited, but it is intended that the invention cover all alternative and equivalent constructions as lmay be included within the spirit and scope of the invention 'as defined by the appended claims.

Turning now to the drawings, there is shown in FIG. l a partial section of the end of a shipping container ernbodying the closure of the present invention. The container comprises -a cylindrical body wall 10 whichmay be constructed of any suitable material such as fibre, paperboard or the like, but may also' be of more conventional metal construction. For illustrative purposes, the exemplary container illustrated in the figures is of fibre construction. A conventional rolled chime construction is used -at each end employing Ian inwardly-projecting circumferential bead or rib 11 adjacent t-o and slightly inset from the mouth 12, or open end, of the container. A metal reinforcing ring 13 is provi-ded at each end of the container body wall 10 t-o complete the chime. The reinforcing `ring 13 is preferably rolled over the mouth 12 of the container and into the depression in the region of the circumferential bead 11 to stiffen and reinforce the container at each end.

As a principal feature of the invention, -a strong, relatively liexible .membrane 1S is drawn over the mouth 12 and pulled down the exterior of the body wall 10 into a depression 14 -in the region opposite the circumferential bead 11, Beneath the membrane 15 is provided an annular sealing gasket 16 which is clamped into sealing engagement between the membrane 15 and the internal. rib 11 by a -contractable closing ring 17 which further serves to stiffen and -reinforce the critical chime 'area of the container. The annular sealing gasket 16 is preferably made of a res'iliently -compressible material which is impervious t-o the contents of the container :and resistant to attack by lany aggressive commodities which might be stored or shipped therein. For this purpose, .materials suchy as foam rubber or 'foam plastic have been found suitable.

The membrane 1S, which is .shown split into its respective components in FIG. 5, comprises a strong, flexible sheet which is Iimpervious to penetration or .att-ack by the contents of the container, and is preferably of laminar construction. An 'inner fabric layer 20, comprising a w-oven ymaterial of natu-ral or artificial libres, is laminated on one or both sides with sheets 21 which are preferably of strong, impervious material su-ch as yfoil or k-raft pape-r liner. For the transport or storage of liquid materials, the lam'inate sheets 21 would be made of material impervious to liquids, and for chemically aggressive materials the lsheets would preferably be coated with an inert plastic material.

Further in accordance with the invention, a portion of the membrane 15 is allowed to protrude radially from beneath the lower edge of the contractable closing ring 17 after the closure has been applied, whereby the folds and wrinkles caused by drawing the membrane 15 over the mouth 12 of the container cause the closing ring 17 to lock the membrane firmly in position, thereby preventing slippage and loosening of the closure. As the membrane 15 is drawn over the mouth 12, it ability to stretch is necessarily limited, so that it substantially conforms to the outer contours of the reinforcing ring 13 only in the region above the depression 14 opposite the bead 11. The folds and wrinkles therefore form naturally in a radial direction in the region of the membrane extending over the depression 14, and over the rest of the outer contour of the reinforcing ring 1-4. The contractable closing ring 17 is accordingly constructed with a depending portion 22 which follows the contour of the bead 11 only a relatively short distance so that a protruding portion 23 of the membrane 15 is allowed to extend radially in foldsy and wrinkles which tend to resist being drawn back underneath the closing ring 17.

-Above the container, an inwardly-extending portion 25 of the closing ring 17 is provided to urge the membrane 15 against the mouth 12 of the container, and additionally against the annular sealing gasket 16. For this purpose, s

the inwardly-extending portion 25 is made to overlie the annular gasket 16 in a manner which sandwiches the gasket between the membrane 15 and the internal portion of the bead 11 in a manner which assures an effective seal in this region. The closing ring 17 may be constructed in any suitable manner, such as providing a split portion by which the ring may be opened slightly and drawn into place around the mouth 12 of the container with clamps or other fasteners. Alternatively, it may comprise a continuous band which is formed in place by rolling or other means. After the contractable closing ring 17 has been secured in place against the mouth 12 of the container, membrane 15 and sealing gasket 16 are thereby tightly clamped together against the mouth 12 and bead 11 of the container, resulting in a strong, rigid closure which is impervious to the contents of the container and resistant to deformation and leakage from loads and shocks which would otherwise cause distortion and gaps in the closure.

There is shown in FIG. 2 a modification of the invention embodying a further feature in which the closure is further strengthened by a reinforcing or stiffening disk 30 interposed between the inner surface of the membrane 15 and the annular sealing gasket 16. The disk 30 may be made of any suitable material such as paperboard, cardboard, or the like, provided that a suitable impervious surface 31 is applied similar to that previously described for the membrane 15. In this embodiment, the outer dimensions of the reinforcing disk 30 substantially correspond with the inner dimensions of the container mouthl 12 so that the disk 36 tits within the mouth 12. The membrane 15 is drawn over the outer surface of the reinforcing ring 13 as previously described. By the provision of the reinforcing disk 30, the membrane 15 is considerably reinforced and, in addition, the step of applying the membrane 15 during construction of the closure is facilitated.

There is shown in FIG. 3 another modification of the invention in which a reinforcing disk 32 is provided which overlies the mouth 12 of the container and is held in sealing relationship against the sealing gasket 16 by the membrane 15 through the clamping action of the closing ring 17. As previously described, the reinforcing disk 32 is preferably provided with an impervious surface 33 similar to that of the disk 30 previously described. The addition of the closing ring 17 with its inwardly-extending portion 25 serves to clamp the membrane 15, disk 32, and sealing gasket 16 into sealing relationship against the mouth 12 of the container and the inner rib caused by the circumferential bead 11. The gasket 16 is thereby compressed into sealing engagement with its associated members. In this embodiment, the reinforcing disk 32 has outer dimensions substantially corresponding to the outer dimensions of the mouth 12 of the container so that it substantially overlies the mouth rather than being received therein as in the embodiment illustrated in FIG. 2.

In FIG. 4 there is illustrated still a further embodiment of the invention in which the reinforcing disk is made in two portions 35, 36. The first portion 35 overlies the mouth 12 of the container as in the embodiment of FIG. 3, and the second portion is received therein as in the embodiment of FIG. 2. As in the other embodiments, an annular sealing gasket 16 is provided which, through the addition of the contractable closing ring 17, is compressed into sealing engagement with the inner surface of the bead 11. The reinforcing disk portions 35, 35 may, alternatively, be made in one piece, so that the resulting reinforcing disk would have the same profile in section as the two portions 35, 36 illustrated in FIG. 4.

A further feature of the reinforcing disks 30, 32, 35, 36 is that they render the membrane 15 considerably more resistant against punctures, in addition to providing enhanced stiffening and resistance to deformation of the container.

It will be understood that in carrying out the present invention, the various reinforcing disks 30, 32, 35, 36 may alternatively be secured to the undersurface of the membrane 15 by adhesives or other means to provide a one-piece closure member which may be applied to the mouth of the container and secured in place with the contractable closing ring 17 in the manner described. In this case, as in all the described embodiments, the membrane 15 is drawn down over the outer surface of the mouth 12 and into the depression 14 opposite the bead 11, where it is clamped in place by the closing ring 17 so that a peripheral radially-extending portion 23 beard ing folds or wrinkles is securely clamped by the closing ring 17 so that it cannot slip back to loosen the effectiveness of the closure.

As a further feature of the invention, there is shown in FIG. 2 a stacking member 38 which nests in the opening within the inwardly-extending portion 25 of the closing ring 17 and mates with a corresponding portion of a con-, tainer stacked on top of it. The stacking member 38 may be of wood, fibre or other suitable material, and need not be impervious to the contents of the containers because it does not have occasion to come in contact with them. While the stacking member 38 is illustrated in connection with the embodiment of FIG. 2, it will be appreciated that it may be used with equal success with the embodiments of FIGS. 3 and 4, each of which have one or more reinforcing disks 30, 32, 35, 36 to provide additional strength to the closure and which will allow additional containers to be stacked one on top of the other. With containers carrying relatively light contents, and having membranes 15 of substantial tensile strength, this feature of the invention may be used with equal success in the embodiment of FIG. l, which does not employ a reinforcing disk as do the other embodiments. As an additional feature, the stacking member 38 not only facilitates stacking of the containers, but it also protects and reinforces the membrane 15 in much the same manner as do the reinforcing disks 30, 32, 35, 36.

I claim as my invention:

1. In a shipping container having a body terminating at one end in a mouth opening and having an internal circumferential bead at one end of Said body adjacent said mouth opening defining an annular ledge therein, a closure comprising, in combination, a closure member including a membrane, said membrane projecting radially over the mouth of said body and substantially conforming to the outer surface of said circumferential bead, a resiliently compressible annular gasket interposed between the inner surface of said closure member and the inner surface of said circumferential bead, and a contractable ring overlying said membrane and bead in clamping relationship to said mouth.

2. A closure according to claim 1 in which a peripheral portion of said membrane protrudes radially in folds from beneath said contractable ring, whereby said membrane is restrained from slipping relative to said mouth opening.

3. A closure according to claim 1 having a stacking member overlying said membrane adjacent to and nesting within the upper periphery of said contractable ring, whereby a container of similar end construction may be stacked thereupon in nesting relationship.

4. A closure according to claim 1 in which a stiienin-g member is interposed between s'aid membrane and said annular gasket, said stitfenin-g member having outer dimensions corresponding with the inner dimensions of said mouth whereby said stiifening member is retained within said mouth.

y5. A closure according to claim 4 in which a peripheral portion of said membrane protrudes radially in folds from beneath said contractable ring, whereby said membrane is restrained from slipping relative to said mouth opening.

6. A closure according to claim 4 having a stacking member overlying said membrane adjacent to and nesting within the upper periphery of said contractable ring, whereby a container of similar end construction may be stacked thereupon in nesting relationship.

7. A closure according to claim 1 in which a stifenng member is interposed between said membrane and said annular gasket, said stiienin-g member having outer di-` mensions substantially corresponding with the outer dimensions of said mouth whereby said stiiening member is retained in overlying relationship thereto.

8. A closure according to claim 7 in which a peripheral portion of said membrane protrudes radially in folds from beneath said contractable ring, whereby said membrane is restrained from slipping relative to said mouth opening.

9. A closure according to claim 7 having a stacking member overlying said membrane adjacent to and nesting within the upper periphery of said contractable ring, whereby a container of similar end construction m'ay be stacked thereupon in nesting relationship.

10. A closure according to claim 1 in which a stiiiening member is interposed between said membrane and said annular gasket, said stifening member comprising a rst portion havin-g outer dimensions substantially corresponding to'the outer dimensions of said mouth whereby said irst portion is retained in overlying relationship thereto, and a second portion, said second portion having outer dimensions corresponding with the inner dimensions of said mouth whereby said second portion is retained within said mouth.

11. A closure according to claim -10 in which a peripheral portion of s'aid membrane protrudes radially in folds from beneath said contractable ring, whereby said membrane is restrained from slipping relative to said mouth opening.

12. A closure according to claim v10 having a stacking member overlying said membrane adjacent to and nesting within the upper periphery of said contractable ring, whereby a container of similar end construction may be stacked thereupon in nesting relationship.

References Cited UNITED STATES PATENTS 2,727,673 12/1955 Bergstrom 229-5.5 2,798,654 7/1957 Gibbs 229-5.7 3,186,620 6/ 1965 Meijers 229-5.7

DAVID M. BOCKENEK, Primary Examiner. 

1. IN A SHIPPING CONTAINER HAVING A BODY TERMINATING AT ONE END IN A MOUTH OPENING AND HAVING AN INTERNAL CIRCUMFERENTIAL BEAD AT ONE END OF SAID BODY ADJACENT SAID MOUTH OPENING DEFINING AN ANNULAR LEDGE THEREIN, A CLOSURE COMPRISING, IN COMBINATION, A CLOSURE MEMBER INCLUDING A MEMBRANE, SAID MEMBRANE PROJECTING RADIALLY OVER THE MOUTH OF SAID BODY AND SUBSTANTIALLY CONFORMING TO THE OUTER SURFACE OF SAID CIRCUMFERENTIAL BEAD, A RESILIENTLY COMPRESSIBLE ANNULAR GASKET INTERPOSED BETWEEN THE INNER SURFACE OF SAID CLOSURE MEMBER AND THE INNER SURFACE OF SAID CIRCUMFERENTIAL BEAD, AND A CONTRACTABLE RING OVERLYING SAID MEMBRANE AND BEAD IN CLAMPING RELATIONSHIP TO SAID MOUTH. 